Weed control at high speed

ABSTRACT

An apparatus and a method for increasing the movement speed of the rail vehicle while carrying out measures for controlling weeds on track systems. A rail vehicle equipped with an apparatus for increasing the movement speed of the rail vehicle while carrying out measures for controlling weeds on track systems.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. § 371of International Application No. PCT/EP2018/062271, filedinternationally on May 11, 2018, which claims the benefit of EuropeanApplication No. 17171521.2, filed May 17, 2017.

FIELD OF THE INVENTION

The present invention relates to the technical field of weed control bymeans of a moving rail vehicle. An apparatus and a method for increasingthe movement speed of the rail vehicle while carrying out measures forcontrolling weeds on track systems are the subject matter of theinvention. A rail vehicle equipped with corresponding means is a furthersubject matter of the present invention.

BACKGROUND OF THE INVENTION

The control of plants on track systems is essential for safety reasons.In particular, the ballast bed has to be cleared and/or kept free ofvegetation. The ballast bed is usually flexible and helps to transmitboth static and dynamic loads uniformly to the substructure. Theinnumerable spaces between the individual stones absorb the enormousweight of travelling trains and the impacts like a buffer.

Plants and the humus held by them can block the interspaces over time,and this can put the safety of the trains at considerable risk.Therefore, growth of all kinds has to be kept away from the tracksystems for safety reasons.

Plant growth on track systems is usually prevented by the application ofherbicides. So-called spray trains are special trains for treatingstretches of rail tracks. They serve to apply herbicides so that weedsdo not grow on the ballast bed.

The quantity of herbicides applied should be kept as low as possibleboth for environmental reasons and for cost reasons. Camera systems witha connected image analysis system can be used in order to identifyplants in the track bed and to control them in a targeted mannerEP1521885B1 discloses, for example, an apparatus for weed control for arail vehicle, which apparatus comprises a camera which identifies weedsand is connected to a computer which identifies weeds. The describedapparatus can be used in order to treat with herbicide only thosesections of track in which weed growth has been established by means ofthe camera and computer. Sections of track which are free of weeds donot have to be treated.

The components which are used for controlling weeds in a spray trainusually have a certain inertia. The camera system with a connected imageanalytics system requires a certain time in order to analyse the imagesrecorded during travelling. Further time is required in order to actuatepumps and valves for applying herbicide. Furthermore, a minimum amountof herbicide has to be applied per unit area in order to achieve thedesired effect; the more quickly the train travels, the more quicklythis quantity has to be provided and applied as accurately as possible.A high speed of the train can lead to quantities of herbicide which areapplied swirling and not reaching where they should reach.

All of this leads to a spray train usually being operated at a low speedof approximately 20 km/h. During the time over which a spray train islocated on a section of track, no other train can move on said sectionat a high speed. A slowly travelling spray train therefore leads to acertain blockage of sections of track.

Proceeding from the described prior art, the objective technical problemwas that of reducing the time required for controlling weeds on tracksystems.

SUMMARY OF THE INVENTION

According to some embodiments of the invention, an apparatus for weedcontrol for a rail vehicle comprises

-   -   means for identifying one or more locations along a stretch of        track, at which location/locations measures for weed control        should be carried out, and    -   control means for weed control at the identified location/the        identified locations,        characterized in that the identification means and/or the        control means are set up such that, while the rail vehicle is        travelling, they execute a movement which is directed opposite        to the movement direction of the travelling rail vehicle.

According to some embodiments of the invention, a method comprises

-   -   moving a rail vehicle along a stretch of track in a movement        direction,    -   identifying at least one location at which a measure for weed        control should be carried out,    -   carrying out the measure for weed control at the at least one        location,        characterized in that, during the movement of the rail vehicle,        means for identifying the at least one location and/or control        means for carrying out the measure for weed control at the at        least one location execute a movement which is opposite to the        movement direction of the rail vehicle in order to reduce the        relative speed between the identification means and/or the        movement means and the at least one location.

According to some embodiments of the invention, a rail vehicle comprisesone or more inventive apparatuses.

The invention will be explained in more detail below, according to someembodiments, without distinguishing between the subjects of theinvention (apparatus, method, rail vehicle). Instead, the followingexplanations are intended to apply in an analogous manner to all of thesubjects of the invention, irrespective of the context (apparatus,method, rail vehicle) in which they are made.

According to some embodiments, the invention serves to control weedsusing a moving rail vehicle.

The term “weed” (plural: weeds) is intended to be understood to meanplants in track systems which develop there, for example, from the soilseed potential or are air-borne. The term is not limited to foliage inthe strict sense, but also comprises grasses, ferns, mosses or woodyplants.

Since weeds present a safety risk for the rail vehicles and the people,animals and/or goods travelling therein, the said weeds should becontrolled.

The term “control” is intended to be understood to mean all measures forpreventing the emergence and/or the propagation of and also measures forreducing weeds.

The term “rail vehicle” is intended to be understood to mean any vehiclewhich can be moved on rails along a stretch of track from one locationto another location by means of drive means. The rail vehicle ispreferably a train (for example a spray train) or a Unimog. The railvehicle can preferably be moved at a speed of at least 30 km/h,preferably at least 40 km/h, further preferably at least 50 km/h, bymeans of the drive means.

The rail vehicle has identification means and control means for thepurpose of controlling weeds. The identification means can serve toidentify at least one location at which a measure for controlling weedsshould be carried out. The control means serve to carry out a measurefor controlling weeds. Identification means and/or control means arefitted to the rail vehicle such that they can execute a movement in adirection which is opposite to the movement direction of the railvehicle. In the text which follows, control means and/or identificationmeans of this kind are also called moving control means and/or movingidentification means.

According to some embodiments, the rail vehicle moving in one directionexecutes a relative movement in relation to the stationary track systemand the plants located therein. Owing to the movement of the movablydesigned control means and/or identification means in the oppositedirection, the relative speed of the control means and/or identificationmeans in relation to the stationary track system and, respectively, theplants located therein is reduced. If the control means and/oridentification means move at the same speed as the rail vehicle, 100% ofthe travelling speed is compensated for. The compensation of thetravelling speed preferably lies in the range of from 10% to 90%, evenmore preferably in the range of from 20% to 80%.

According to some embodiments, the rail vehicle travels in one directionwhile the control means execute a movement in the opposite direction andin the process carry out a measure for controlling weeds.

According to some embodiments, the rail vehicle travels in one directionwhile the identification means execute a movement in the oppositedirection and in the process identify locations at which a measure forcontrolling weeds is to be carried out.

According to some embodiments, the rail vehicle moves in one directionwhile the identification means execute a movement in the oppositedirection and in the process identify locations at which a measure forcontrolling weeds is to be carried out, and the control means likewiseexecute a movement in the opposite direction and in the process executea measure for controlling weeds at the identified locations.

According to some embodiments of the present invention, weed control isperformed by applying one or more herbicides. The said herbicides may beselective herbicides which kill certain plants in a targeted manner, orso-called total herbicides which act against a very large number ofplants. In some embodiments, a combination of selective and totalherbicides may be used. The preferably moving control means arepreferably spray nozzles which are connected to a container containing aherbicide formulation by means of at least partially flexible lines.

According to some embodiments of the present invention, weed control isperformed by flaming. The preferably movably designed control means arepreferably one or more nozzles from which a combustible material canemerge, it being possible for the said combustible material to beinduced to burn by means of an ignition apparatus.

According to some embodiments of the present invention, weed control isperformed by freezing, for example by applying liquid nitrogen. Thepreferably movably designed control means are preferably one or morenozzles from which liquid nitrogen can be dispensed.

According to some embodiments of the present invention, weed control isperformed by the action of electromagnetic radiation, for example byx-ray radiation, ultraviolet radiation, infrared radiation, microwaveradiation or strongly focused visible radiation, for example by means oflaser radiation. The preferably movably designed control means arepreferably means for emitting radiation in the direction of plants whichare located on the track system. These means may be radiation sourcesfor electromagnetic radiation. In some embodiments, said means are meanswith which electromagnetic radiation is guided in a defined direction,such as mirrors, lenses and/or prisms or the like, for example.

According to some embodiments of the present invention, weed control isperformed by the application of current. The preferably movably designedcontrol means are preferably electrodes through which an electriccurrent can be made to flow upon contact with a plant, the said electriccurrent flowing at least partially through parts of the plant.

According to some embodiments, a combination of two or more of the saidweed control measures is also feasible.

According to some embodiments, the measures for weed control areperformed as a rail vehicle travels along a stretch of track.

According to some embodiments, the weed control is preferably performedat a speed of at least 30 km/h, preferably at least 40 km/h, even morepreferably at least 50 km/h.

In some embodiments, a weed control measure takes a certain amount oftime. For example, a minimum energy in the form of electrical energy orthermal energy or electromagnetic energy has to be introduced into aplant in order to kill the said plant. In some embodiments, for example,a minimum contact time between the plant and an electrode has to bemaintained in order to reach this minimum energy. In some embodiments,the plant has to be exposed to radiation, for example, for a minimumperiod of time in order to reach the minimum energy. In someembodiments, valves require a certain amount of time in order to openand herbicides require a certain amount of time in order to be expelledfrom a nozzle.

Furthermore, it is conceivable that the high relative speed betweencontrol means and weeds which results owing to the travelling railvehicle has a negative influence on the control measure. For example, itis conceivable that the airspeed which increases as the speed of therail vehicle increases leads to undesired distribution of the sprayedherbicide.

Therefore, according to some embodiments of the invention, the relativespeed between the control means and the weeds which are to be controlledis reduced owing to a movement of the control means opposite to themovement direction of the rail vehicle.

For example, according to some embodiments, it is feasible that thecontrol means are mounted in a movable manner on a rail on the railvehicle. While the rail vehicle moves in one direction (for example“forwards”), the control means which are mounted on the rail can move inthe opposite direction (“backwards”), in a manner driven by a motor forexample, on the rail and perform a measure for weed control with thismovement.

In some embodiments, the rail is closed and, after a distance alongwhich the control measure is executed, leads back to the start again.The rail could be designed, for example, in the form of an “elongatezero”. An “elongate zero” has two parallel straight sections which areconnected to one another by means of two preferably semicircular bends.On one of the straight sections, the control means move opposite to themovement direction of the rail vehicle and in the process execute acontrol measure. The said control means are then guided onto the secondstraight section via the first bend and move on the second straightsection in the same direction as the rail vehicle. During this movementin the travelling direction, the said control means preferably do notexecute a control measure. The said control means then reach the secondbend and are guided onto the first straight section again by the secondbend.

According to some embodiments, a plurality of control means are guidedon the inherently closed rail, so that there is always at least onecontrol means on a straight section on which the control means movesopposite to the travelling direction of the rail vehicle. In this way,at least one control means is always in use.

According to some embodiments, the control means may be fastened to acircumferential support, as is known, for example, in the case oftracked vehicles or escalators.

According to some embodiments, in addition to the lateral movement ofthe control means, the movement of the control means may include apivoting movement. For example, in some embodiments, a source ofelectromagnetic radiation may pivot against the travelling directionwhile the rail vehicle is travelling, so that, for example, a region ofthe track bed beneath the rail vehicle is irradiated during the pivotingperiod. In some embodiments, a plurality of control means may be usedwhich pivot to and fro in parallel, so that at least one control meansalways performs a pivoting movement opposite to the travelling directionof the rail vehicle. In some embodiments, a rotation movement instead ofa pivoting movement may be used.

According to some embodiments, the weed control is carried out at one ormore locations along a stretch of track for which location/locationsweed control has been displayed.

Therefore, according to some embodiments, a location at which weedcontrol should be performed is first determined (identified) and thenthe corresponding weed control is performed at this location. A furtherlocation along the stretch of track can then be determined (identified),and corresponding weed control is performed at the further location. Alocation is usually a section of track in which weeds have beendiscovered and/or a section of track in which there is a risk of weedsoccurring.

According to some embodiments of the present invention, a location isidentified by a camera system which is equipped with means for imageanalysis. The camera system (or parts thereof, such as the camera opticsfor example) is (possibly movably) fastened to the rail vehicle andrecords images of the track system during travelling. The recordedimages are analysed for the presence of plants or parts of plants. If aplant is identified in an image, the location at which the image hadbeen recorded and at which the plant is located is determined(identified) as a location at which weed control should be performed.

In some embodiments, plants are identified as such by the camera system.In some embodiments, the camera system is designed such that it canidentify an individual plant species.

According to some embodiments, in order to record an image of an object,light which is incident on the object and is returned(reflected/scattered) is detected by an image sensor (for example CCDsensor, CMOS sensor) and converted into electrical signals. In someembodiments, images of the area surrounding a rail vehicle are generatedas the rail vehicle moves at a relative speed in relation to theenvironment. In order to avoid motion blur, the exposure time can bematched to the speed. The greater the relative speed, the lower themaximum exposure time which may not be exceeded in order to comply witha prespecified (tolerable) motion blur.

A shorter exposure time can be compensated for, for example, by a higherquantity of light. According to some embodiments of the presentinvention, a higher speed of the rail vehicle is compensated for by arelative movement of the camera opposite to the movement direction ofthe rail vehicle. To this end, the camera can be movably mounted, forexample, on a rail on the rail vehicle. As the rail vehicle travels inone direction, the camera is moved, for example in a manner driven by amotor, in the opposite direction in order to reduce the relative speedbetween the camera and the area surrounding the rail vehicle (forexample track bed).

In some embodiments, during the movement, the camera covers a distanceopposite to the movement direction of the rail vehicle and, during thismovement, generates a plurality of image recordings of the surroundingarea (for example the track bed). The camera is then moved back to itsoriginal location again. During this return movement, the relative speedbetween the camera and the area surrounding the rail vehicle isnaturally greater than the relative speed between the rail vehicle andthe surrounding area. Therefore, preferably no image recordings of thesurrounding area are generated during this return movement. However, inorder that the rail vehicle is not “blind” during this return movement,at least one further camera can be used, which camera alternates withthe first camera for generating image recordings.

In some embodiments, in addition to the lateral movement of thecamera(s), the movement of the camera(s) may include a pivotingmovement. For example, in some embodiments, a plurality of images of theobject which is intended to be identified or specified as a weed arerecorded from different viewing angles for the purpose of identifyingweeds or the weed species present. For example, according to someembodiments, an object which has, for example, a green colour isidentified in a first image which has been recorded by a camera from oneviewing angle. As is known, a large number of plants at least partiallyhave a green colour, which is attributed to the presence of chlorophyll.In some embodiments, the camera pivots against the travelling directionof the rail vehicle in order to generate at least one further imagerecording of the object from a different viewing angle for the purposeof ensuring that the green object is a plant or for identifying theplant species present. In some embodiments, a three-dimensionalreproduction of the object is generated from a plurality of imagerecordings from different viewing angles. The more image recordings ofan object generated from different viewing angles, usually the higherthe accuracy for identifying the object.

According to some embodiments of the present invention, the at least onelocation at which weed control should be performed is not determinedduring travelling of the rail vehicle, but rather in advance, and thefact that the previously defined location has been reached is (merely)displayed during travelling of the rail vehicle. For example, in someembodiments, remote sensing data may be used in order to identifylocations along stretches of track on which weeds are growing.

Remote sensing data is digital information which is acquired from adistance, for example of the Earth's surface by satellites. In someembodiments, use of aircraft (unmanned (drones) or manned) may be usedfor recording remote sensing data.

In some embodiments, remote sensing data is analysed for the presence ofweeds in the region of the rail network of a rail operator and thegeocoordinates of locations at which weeds have been identified aredetected. As the rail vehicle moves along a stretch of track in which atleast one such location is located, the respective position of the railvehicle is monitored by means of a position determining system (forexample GPS-assisted). As the rail vehicle approaches a location of thiskind, the preparations for weed control are performed. If the positiondetermining system identifies that the rail vehicle is located at alocation of this kind, the weed control measure is executed.

However, it is also conceivable that there is a digital map on whichlocations at which specific measures for weed control should not becarried out are listed. For example, it is conceivable that herbicidesmust not be applied in some regions along a stretch of track forenvironmental or water protection reasons. It is likewise conceivablethat electrical energy must not be used in order to kill plants in somelocations, for example because sensitive electrical or electronicinstallations which can be disturbed or damaged by the use of electricalenergy are located in the vicinity. Therefore, according to someembodiments, those locations at which a weed control measure should beinterrupted are displayed (identified), while the measure is performedat all other locations.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below with reference tofigures, without the invention intending to be restricted to thefeatures and combinations of features shown in the figures, in which:

FIG. 1 schematically shows a rail vehicle equipped with an apparatusaccording to some embodiments of the invention.

FIG. 2 schematically shows a further rail vehicle equipped with anapparatus according to some embodiments of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The rail vehicle (10) shown in FIG. 1 is illustrated from one side (a)and from below (b). The said rail vehicle moves in a direction (50) onrails (20) by means of wheels (30). A camera system (40) by way of whichthe track bed can be examined for the presence of weeds is provided. Ifweeds or a specific weed are/is identified by means of the camerasystem, a control means is activated. In this embodiment, weed controlis performed by the application of a herbicide. The herbicide is appliedto the track bed by means of spray nozzles (60, 60′, 61, 61′). FIG. 1shows two spray nozzles (60, 60′) which move on rails (70, 70′) in adirection which is opposite to the movement direction (50) of the railvehicle (10). These spray nozzles (60, 60′) apply herbicide to the trackbed as they move in the said direction. During this time, the spraynozzles (61, 61′) move on the same rails (70, 70′) but in the direction(50) of the rail vehicle and do not apply herbicide in the process. Thesaid spray nozzles apply a herbicide only when they have reached therespectively outer straight section beyond the bends in the rails andexecute a movement opposite to the direction (50) of the rail vehicle.The spray nozzles (60, 60′) then move in the direction (50) of the railvehicle to the inner straight section and do not perform applicationduring this movement.

The rail vehicle (10) shown in FIG. 2 moves in a direction (50) on rails(20). The rail vehicle is equipped with identification means (40) in theform of a camera. In the upper illustration (a1), the camera is lookingat a section of track in the travelling direction (50). In the lowerillustration (a2), the rail vehicle is shown at a later moment; it hasmoved slightly to the right in relation to the position in theillustration (a1). During this movement, the camera (40) has completed apivoting movement opposite to the movement of the rail vehicle (to therear); in the illustration (a2), the camera is directed to the left.During the pivoting movement, the camera takes one or more imagerecordings of the track bed in order to identify weeds. If a weed isidentified, a spray nozzle (60) is prompted to apply a herbicide whenthe weed is in the application range of the spray nozzle. After thepivoting movement to the rear, the camera will perform a pivotingmovement forwards into its starting position in order to then once againpivot to the rear, and so on. While pivoting forwards, said camera doesnot take any image recordings. A plurality of cameras are preferablyprovided, which cameras alternately pivot from front to rear and back,wherein at least one camera always performs a pivoting movement againstthe movement direction of the rail vehicle and in doing so generates oneor more image recordings of the track bed in order to identify weeds.

1: An apparatus for weed control for a rail vehicle, comprising: anidentification system for identifying one or more locations along astretch of track for weed control, and a weed control system forapplying weed control at the identified one or more locations, wherein,at least one of the identification system and the weed control system isconfigured to move in a direction that is opposite to a movementdirection of the rail vehicle. 2: The apparatus of claim 1, wherein theweed control system comprises nozzles. 3: The apparatus of claim 1,wherein the weed control system comprises spray nozzles for applying oneor more herbicides. 4: The apparatus of claim 1, wherein the weedcontrol system comprises electrodes for applying an electric currentupon contact with a plant so that the electric current flows at leastpartially through the plant. 5: The apparatus of claim 1, wherein theweed control system comprises at least one emitter for emittingradiation in a direction of plants located on the track system. 6: Theapparatus of claim 1, wherein the identification system comprises one ormore cameras which are connected to a computer system for analysingimages. 7: A method comprising: moving a rail vehicle along a stretch oftrack in a movement direction, identifying, via an identificationsystem, at least one location for weed control, and applying, via a weedcontrol system, the weed control at the at least one location, wherein,during the movement of the rail vehicle, at least one of theidentification system and the weed control system moves in a directionthat is opposite to the movement direction of the rail vehicle. 8: Themethod of claim 7, wherein the rail vehicle moves at a speed of at least30 km/h, while the weed control system applies the weed control. 9: Themethod of claim 7, wherein at least a portion of at least one of theidentification system and the weed control system is mounted on a railand carries out a lateral movement opposite to the movement direction ofthe rail vehicle. 10: The method of claim 9, wherein the rail forms aclosed loop. 11: The method of claim 7, wherein at least a portion of atleast one of the identification system and the weed control system isfastened to a circumferential support and carries out a lateral movementopposite to the movement direction of the rail vehicle. 12: The methodof claim 7, wherein at least a portion of at least one of theidentification system and the weed control system is pivotably mountedand carries out a pivoting movement opposite to the movement directionof the rail vehicle. 13: The method of claim 7, wherein at least one ofthe identification system and the weed control system comprises aplurality of portions that carry out a rotation movement and a portionof the plurality of portions that is located closest to the track bedcarries out a movement opposite to the movement direction of the railvehicle. 14: The method of claim 7, wherein at least one of theidentification system and the weed control system comprises a pluralityof portions and a portion of the plurality of portions is configured toalways move in a direction opposite to the movement direction of therail vehicle. 15: A rail vehicle comprising one or more apparatuses ofclaim
 1. 16: The method of claim 7, wherein the rail vehicle moves at aspeed of at least 40 km/h while the weed control system applies the weedcontrol. 17: The method of claim 7, wherein the rail vehicle moves at aspeed of at least 50 km/h while the weed control system applies the weedcontrol.